This is a simple port of the classic PalmOS game Vexed. For now, it uses largely the same block sets and levels as the original, but that might change in the future. It looks something like this:

It's available as a $US1 (approximately - I have to price in £) download from the market - and for those who can't, or don't want to, pay it's available here for free. If anyone's interested, the source code is also available...